The Immune Response in Periodontal Tissues.

The uniqueness of periodontal diseases is caused by several factors. This group of diseases is caused by numerous bacterial species formed in the dental biofilm, and one cannot distinguish the specific pathogen that is responsible for the disease initiation or progress (though Gram-negative anaerobic rods are associated with the advanced form of the disease). The disease is both infectious and inflammatory in its nature, and in the state of health there is always a subclinical level of inflammatory response, caused by the so-called harmless bacteria. Negligence in oral hygiene may result in maturation of the biofilm and trigger host response, manifesting clinically as gingivitis or-later and in susceptible subjects-as periodontitis. The article presents the contemporary knowledge of the inflammatory reaction occurring in tissues surrounding the tooth during periodontal inflammation. The most important mechanisms are described, together with implications for clinicists.

Una alternativa para mejorar el diagnóstico de la tuberculosis con baciloscopia negativa y otros problemas broncopulmonares en Cuba / An alternative for improving the diagnosis of smear-negative tuberculosis and other bronchopulmonary disorders in Cuba

OBJETIVO: El diagnóstico de los pacientes con tuberculosispulmonar y muestras negativas para bacilos ácido-alcoholresistentes (BAAR) representa un desafío clínico y de saludpública, por lo que en Ciudad de La Habana se creó en 1995una comisión para esclarecer su diagnóstico. El objetivo deeste estudio ha sido describir los progresos y resultados deltrabajo de esta comisión entre 1996 y 2003.PACIENTES Y MÉTODOS: Se han analizado los datos recogidosde cada paciente presentado en las sesiones de la comisión:procedencia, diagnóstico de sospecha planteado por el médicoque presentó el caso, antecedentes de tratamiento anteriorcon antibióticos y diagnóstico realizado por la comisión.RESULTADOS: Del total de 1.703 pacientes presentados aesta comisión para esclarecer el diagnóstico, un 84,8%procedía de la Ciudad de La Habana, el 48,4% pertenecía algrupo de edad igual o mayor de 55 años y el 63,8% eranvarones. El porcentaje de casos consultados con tratamientoespecífico contra la tuberculosis ya comenzado fue en 2001-2003 del 11,3%, y en el período 1996-2000, del 16,9% (p =0,001). En 1986-2000, de 918 pacientes que completaron susexámenes, tuvo diagnóstico final de tuberculosis activa un43,1%, y en 2001-2003, el 52,2% de 619 (p = 0,000). De untotal de 344 casos estudiados con sospecha de tuberculosispulmonar con BAAR y cultivo negativos en 2001-2003, eldiagnóstico se corroboró en 128 (37,2%).CONCLUSIONES: Los resultados indican que el trabajo dela comisión es viable, sostenible y de utilidad porque evita elsobrediagnóstico y el tratamiento inapropiado, además decumplir una función docente

OBJECTIVE: The diagnosis of tuberculosis in patients withnegative acid-fast bacillus smears poses a challenge to bothclinicians and public health authorities. In an attempt to aiddiagnosis in such cases, an expert committee was establishedin Ciudad de La Habana, Cuba in 1995. The aim of this studywas to describe the progress of the committee’s work and thecorresponding results for the period 1996 through 2003.PATIENTS AND METHODS: For each patient studied by thecommission, we analyzed the following data: patient’sresidence and referring center, tentative diagnosis proposedby the attending physician, history of antibiotic treatment,and final diagnosis made by the commission.RESULTS: Of the 1703 patients studied, 84.8% were from LaHabana, 48.4% were 55 years or older, and 63.8% were men.Between 2001 and 2003, 11.3% of patients were already onantituberculosis treatment when their case was studied by thecommission. The corresponding percentage for 1996 through2000 was 16.9% (P=.001). Active tuberculosis was confirmedin 43.1% of a total of 918 patients with full test results duringthe period 1996 through 2000 and in 52.2% of a total of619 patients (52.2%) during the period 2001 through 2003(P<.001). Of 344 patients with suspected pulmonary tuberculosisand negative acid-fast bacillus smears between 2001 and 2003,128 (37.2%) were diagnosed with active tuberculosis.CONCLUSIONS: These findings indicate that the work of thecommission is viable, sustainable, and useful for preventingoverdiagnosis and inappropriate treatment, and that it also serves an educational purpose

The function and biological role of toll-like receptors in infectious diseases: an update.

PURPOSE OF REVIEW: The present review summarizes exciting new findings and reports recent advances in the understanding of the role of toll-like receptors in health and disease. It intends to provide a rough survey on topics discussed by researchers in the field and to stimulate discussion on new aspects of the complex processes involved in innate host defence. RECENT FINDINGS: Novel findings have been reported on the many aspects of toll-like receptors biology, namely the receptor structure and the molecular process of ligand recognition, receptor assembly, cellular localization and trafficking, downstream signaling and the regulatory factors involved, genetic polymorphisms within receptor genes and their linkage to human diseases, and the functional role of toll-like receptors in immune defence and host-microbe homeostasis. SUMMARY: Recent advances have allowed a more detailed picture not only of the processes involved in microbial recognition and host defence but also revealed unexpected insights into the cause of inflammatory processes and the close interrelationship between the vertebrate host and the microbially colonized environment.

Changes in pools of autoantibodies and anti-bacterial antibodies in patients suffering from recurrent infections of the urinary tract and undergoing bacterial immunization treatment.

Antibodies (Abs) (IgM, IgA, IgG and IgG subclasses) specific for several uropathogenic strains (Escherichia coli, Pseudomonas sp. and Klebsiella sp.) as well as anti-phospholipids, anti-beta2-glycoprotein I and anti-laminin antibodies were analyzed in the sera of 20 patients with long-lasting uncomplicated recurrent infections of the lower urinary tract who underwent immunization treatment with a mixture of heat-inactivated bacteria. Immunization had a dual effect: a marked prolongation of the infection-free period in more than half of tested patients (which could be related to the profiles of anti-bacterial antibodies), and the induction of a significant decrease in autoreactivity. The results obtained showed that prolonged infections resulted in a significant rise in IgG specific for phospholipids, beta2-glycoprotein I and mouse laminin. However, irrespective of the effect on urinary tract infection per se, immunization induced a noticeable decrease in reactivity toward those antigens (Ag). The most abundant autoantibodies prior to immunization treatment were of IgG2 subclass. A statistically significant decrease in phospholipid specific antibodies belonging to this subclass, and in the concentration of Y7 cross-reactive idiotope, registered only in the responder group; this indicates the significance of natural antibody pool involvement in a proper anti-bacterial immune response.

Development, characterization, and preliminary evaluation of a temperature-sensitive mutant of Ornithobacterium rhinotracheale for potential use as a live vaccine in turkeys.

A temperature-sensitive (Ts) mutant strain of Ornithobacterium rhinotracheale (ORT) was developed after exposure of the wild-type organism to N-methyl-N'-nitro-N-nitrosoguanidine. The Ts mutant strain grew at 31 C but had its growth inhibited at 41 C unlike wild-type parent strain. The Ts mutant and parent strains were characterized. Morphologic and biochemical properties of wild-type and mutant strains did not show any differences. The strains were also characterized by polymerase chain reaction (PCR)-based fingerprinting methods. Results showed similar patterns in repetitive sequences by repetitive PCR (enterobacterial repetitive intergenic consensus, highly conserved repeated DNA elements present in Streptococcus pneumoniae (BOX), repetitive extragenic palindromic, and Salmonella enteritidis repetitive element primers); however, random amplified polymorphic DNA fingerprinting was able to differentiate mutant and parent strains showing a unique pattern for each of the ORT strains. The rationale for the use of a Ts strain as a vaccine is based on the ability of the mutant to colonize the upper respiratory tract but not the lower respiratory tract and systemic system of the birds, where the wild-type strain causes severe lesions. In a preliminary evaluation, Ts strain of ORT was recovered from tracheas and choanae of Ts-treated turkeys for 13 days postadministration of the strain either in drinking water or by oculonasal instillation. Humoral immune response was detected in Ts-vaccinated but not in control group birds after 3 wk postadministration. Results suggest that Ts strain of ORT has promising potential use as a live vaccine for ORT.

Minimization of pathologic changes in Ornithobacterium rhinotracheale infection in turkeys by temperature-sensitive mutant strain.

The protection elicited by a temperature-sensitive (Ts) mutant of Ornithobacterium rhinotracheale (ORT) vaccine against challenge with pathogenic strain was investigated. In Experiment 1, specific serologic response to ORT was detected in 12%-19% of Ts-vaccinated birds at 3 wk postvaccination by either drinking water or oculo-nasal instillation. At 7 days postchallenge, 100% of Ts-vaccinated turkeys of all groups were able to respond with an ORT-specific antibody response, but the control group was not, suggesting the potential of Ts strain to evoke immune protection. The study also revealed a statistically significant ability of the Ts strain to protect vaccinated turkeys against gross lesions caused by the pathogenic strain of ORT in treated groups vs. control. In Experiment 2, seroconversion was detected by enzyme-linked immunosorbent assay in birds after they were given the Ts strain in drinking water in field conditions. The results of the field study showed mean scores of gross lesions of nonvaccinated/challenged groups to be up to seven times higher than those of the vaccinated/challenged group. In addition, reisolation rates and quantification of ORT colonies per gram of lung tissue were significantly lower for vaccinated/challenged than for nonvaccinated/challenged turkeys. In conclusion, results from laboratory and field experiments suggest that use of the Ts mutant strain of ORT as a live vaccine would be a suitable method to evoke protection against ORT infection in turkeys.

[Chemical characterisation and serological activity of lipopolysaccharides of Ralstonia solanacearum]. / Khimicheskaia kharakteristika i serologicheskaia aktivnost' lipopolisakharidov Ralstoniia solanacearum.

Lipopolysaccharides (LPS) of 8 strains of Ralstonia solanacearum (767, 4157, 5712, 7944, 7945, 7955, 8089 and 8110) characterized by different types of the structures of O-specific polysaccharide chains have been investigated. The ELISA and ELISA-inhibition methods were used to investigate the extent of antigenic activity of the presented LPS with respect to the obtained polyclonal O-antisera to the above strains. When analyzing the results obtained the strains were divided into five serogroups as the result of biochemical and serological investigations. The first serogroup included the strains 5712, 7945, 7955 and 8110, whose LPS and O-antisera were characterized by the high level of serological affinity. The second and the third serogroups included the strains 767 and 7944, respectively. Their LPS demonstrated antigenic specificity in the homologous systems only, as well as to O-serum to the strain 5712. The fourth and the fifth serogroups included strains 4157 and 8089, respectively, whose LPS did not manifest the antigenic specificity with respect to O-antisera of the other strains, besides their own ones, and which were characterized by different in principle types of the O-PS structures O-PS.

Vaccination of ducks with recombinant outer membrane protein (OmpA) and a 41 kDa partial protein (P45N') of Riemerella anatipestifer.

The generation of protective immunity against Riemerella anatipestifer infection in ducks were investigated by immunizations with recombinant glutathione sulfatransferase (GST) fusion's proteins of OmpA, a 42kDa major outer membrane protein, and P45N', a 41kDa N-terminal fragment of a newly identified 45kDa potential surface protein from R. anatipestifer. The DNA encoding OmpA and P45N' were isolated from R. anatipestifer serotype 15 (field strain 110/89) and serotype 19 (reference strain 30/90), respectively. Immunoblotting and ELISA results showed that the purified recombinant proteins induced the production of antibodies in immunized ducks. However, neither was protective against subsequent challenge with the virulent serotype 15 strain, 34/90. All the five ducks immunized with formalinized R. anatipestifer strain 34/90 survived the challenge with the homologous strain whereas six out of seven ducks in the non-immunized control group died within a week following the challenge.

Seroprevalence of Ornithobacterium rhinotracheale infection in commercial laying hens in the north central region of the United States.

This study was the first to examine the seroprevalence of Ornithobacterium rhinotracheale (ORT) within a commercial egg layer population. Serum samples collected from egg production companies were examined by serum plate agglutination test (SPAT) and outer membrane protein-based enzyme-linked immunosorbent assay (ELISA). Results show that 90% of layer flocks were positive by SPAT and 100% by ELISA. Of the pullet flocks examined, 43% and 52% were positive by SPAT and ELISA, respectively. Our study indicates that the prevalence of ORT antibody is high in the commercial layer population, suggesting that this respiratory pathogen can easily spread through multiple-age layer farms from older flocks to newly housed pullet flocks.

Phenotypic and molecular characterization of isolates of Ornithobacterium rhinotracheale from Peru.

Twenty-five isolates of Ornithobacterium rhinotracheale were examined by agar gel precipitation, immunoperoxidase assay, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, western blot analysis, and a polymerase chain reaction. All of the isolates were identified as serotype A. Protein profiles of whole cell extracts were similar for all the isolates, and a polypeptide with a molecular weight of 33 kD was a major component, being present in all the isolates. In the main, proteins of 33, 42, 52, and 66 kD were recognized in immunoblots with sera from chickens naturally exposed to O. rhinotracheale. A modified polymerase chain reaction assay identified O. rhinotracheale DNA from all the isolates and tracheal swabs, producing amplicons of 784 bp, and distinguished O. rhinotracheale from bacterial agents causing similar clinical signs.

[Mechanisms behind the development of antibiotic resistant bacteria]. / Mekanismer for utvikling av antibiotikaresistente bakterier.

BACKGROUND: Bacterial resistance to antibiotics is an increasing threat to the successful treatment of hospital and community-acquired infections. MATERIAL AND METHODS: Based on relevant literature, this article focuses on some of the essential resistance problems caused by pathogens such as pneumococci, staphylocci, enterococci and gram-negative rods, and provides a review of the genetic and molecular basis of bacterial resistance, as well as of the global trends in bacterial resistance. RESULTS: Mechanisms of resistance continue to evolve and disseminate among gram-negative as well as gram-positive pathogens. New problems are developing, such as glycopeptide resistance in Staphylococcus aureus. Bacteria have become resistant to antibiotics as a result of chromosomal changes or the exchange of genetic material via plasmids and transposons. The emergence of multiresistant bacteria e.g. S. aureus, enterococci and Mycobacterium tuberculosis, has made many currently available antibiotics ineffective. INTERPRETATION: The introduction of new antibiotics has always been followed by development of resistance.

Characterization of a predominant immunogenic outer membrane protein of Riemerella anatipestifer.

The ompA gene, encoding the 42-kDa major antigenic outer membrane protein OmpA of Riemerella anatipestifer, the etiololgical agent of septicemia anserum exsudativa, was cloned and expressed in Escherichia coli. Recombinant OmpA displayed a molecular mass similar to that predicted from the nucleotide sequence of the ompA gene but lower than that observed in total cell lysates of R. anatipestifer. The ompA gene showed a conserved C-terminal region comprising the OmpA-like domain and a variable N-terminal region. This structure is similar to those of the analogous outer membrane proteins of several gram-negative bacteria. However, OmpA of R. anatipestifer contains six EF-hand calcium-binding domains and two PEST regions, which distinguish it from other outer membrane proteins. The occurrence of these motifs in OmpA suggests a possible role in virulence for this protein. The ompA gene is present in the R. anatipestifer type strain and in all serotype reference strains. However, it exhibits some minor genetic heterogeneity among different serotypes, which seems not to affect the strong antigenic characteristics of the protein. OmpA is a conserved and strong antigenic determinant of R. anatipestifer and hence is suggested to be a valuable protein for the serodetection of R. anatipestifer infections, independent of their serotype.

[Ornithobacterium rhinotracheale infections in poultry: a review]. / Ornithobacterium rhinotracheale infecties bij pluimvee: een overzicht.

O. rhinotracheale is a relatively new bacterium. It is found in commercial fowl and wild birds throughout the world. O. rhinotracheale causes respiratory disease, presenting as pneumonia and air sacculitis. It is transmitted horizontally as well as vertically. O. rhinotracheale is difficult to isolate. Serologically, twelve serotypes can be distinguished, of which serotype A is the most prevalent. Treatment can be difficult, because acquired resistance against the regular antibiotics is common in O. rhinotracheale isolates. An inactivated vaccine for broiler breeders has been developed and for turkeys an inactivated autovaccine can be made.

Outer membrane proteins for serologic detection of Ornithobacterium rhinotracheale infection in turkeys.

Ornithobacterium rhinotracheale (ORT) is a bacterium responsible for a respiratory disease in turkeys and chickens and has been identified as one of the emerging respiratory bacterial pathogens. The clinical signs and lesions caused by ORT are very similar to those caused by other respiratory infectious agents; therefore, an accurate diagnostic test is necessary to identify the infection. In this study, we have investigated the use of outer membrane proteins of ORT in an indirect enzyme-linked immunosorbent assay (ELISA) to detect the exposure to ORT infection. Outer membrane proteins of ORT were extracted and used as an antigen in ELISA to detect infection in turkeys exposed to different serotypes of ORT. The ELISA results were compared with the conventional serum plate agglutination test. The agglutination test detected specific antibodies for ORT in 65% of experimentally infected turkeys during the first 2 wk of infection. The ELISA detected up to 100% of infected birds for 8 wk postinfection. The results suggest that ELISA is able to detect the exposure to ORT in later stages of the infection and this assay can be used in serologic surveillance of ORT infection for poultry in the field.

Specificity of monoclonal antibodies to Campylobacter jejuni lipopolysaccharide antigens.

Monoclonal antibodies (Mabs) were produced to the lipopolysaccharide antigens of Campylobacter jejuni strain 1249 (Penner serotype O:2/63). A polymyxin-cloth based enzyme immunoassay (pCEIA) was used for initial screening and for evaluating the specificity of these antibodies. Seven Mabs reacted with at least 11 and as many as 14 of 15 C. jejuni strains (representing 8 different Penner serotypes). These seven Mabs did not cross-react with any of 16 non-Campylobacter bacteria commonly encountered in food, with only two exceptions. Several combinations of these Mabs in pairs reacted with all 15 C. jejuni strains. These results suggest that pCEIA employing two of these Mabs in combination is potentially useful for detection of Campylobacter jejuni in foods and other samples.